1. Field of the Invention
The present invention relates to a rotary electric machine such as an automotive alternator, and particularly relates to a stator winding mounting construction for a stator core in which slots are formed at a ratio of two slots per phase per pole.
2. Description of the Related Art
In conventional rotary electric machines, a stator is formed so as to have a slot count at a ratio of two slots per phase per pole, and an armature winding is constituted by two three-phase wye-delta hybrid windings. Moreover, the three-phase wye-delta hybrid windings include: a delta winding in which three phase windings are delta-connected; and a wye winding that is constituted by three phase windings that are connected to respective output ends of the delta winding.
However, in wye-delta hybrid windings, when only the fundamental wave is considered, an electric current that is √3 times the electric current that flows through the phase windings of the delta winding flows through the phase windings of the wye winding. Thus, one problem has been that the density of the electric current that flows through the phase windings of the wye winding and the density of the electric current that flows through the phase windings of the delta winding are different, and temperature distribution in the stator winding is nonuniform.
In order to make the temperature distribution of a stator winding that is constituted by a wye-delta hybrid winding uniform in view of these conditions, it has been proposed that the density of the electric current that flows through the phase windings of the wye winding and the density of the electric current that flows through the phase windings of the delta winding be made equal by freaking the turn count of the phase windings of the wye winding identical to the turn count of the phase windings of the delta winding, and making the cross-sectional area of the conductor wires that constitute the phase windings of the wye winding √3 times the cross-sectional area of the conductor wires that constitute the phase windings of the delta winding (see Patent Literature 1, for example).
Patent Literature 1: WO/2005/107040 (Pamphlet: FIG. 6)
Thus, in conventional rotary electric machines according to Patent Literature 1, two kinds of conductor wires that have different cross-sectional areas are used in order to make the temperature distribution of the stator winding uniform. Thus, the rigidity of the two kinds of conductor wires is different, and one problem has been that differences arise in the bendability of the two when the coil ends are bent and shaped, making the coil ends nonuniform. Another problem has been that it is necessary to shape the coils using dedicated tools for each of the two kinds of conductor wires, hindering rationalization of the manufacturing process.